[general1465]

So maybe having some hybrid like Slack/Teams over email? Where UI of such email client is rendering emails as a room/channel and subject is the name of the room (removes RE, FW, ...) and works like room identification?. So you will get IRC like experience. If you will add PGP on top of it, it can be also secure and decentralized.

[AJ007]

Delta Chat certainly could emerge in that direction. https://delta.chat/

[lostlogin]

The ‘reactions to emails’ thing that Outlook does is gross. However I avoid most chat apps and dislike email so I’m probably not a representative user.